Measurement capability includes VSWR, return loss, cable loss, and distance-to-fault (DTF) analysis, using frequency domain reflectometry (FDR) technology. Patented RF interference rejection enables accurate measurements in the presence of high RF activity. Data Analysis software enables assessment of system trends, problems, and performance in addition to professional report generation. Optional power monitor is available to make power measurements quickly and easily. Built-in GPS receiver (optional) provides location information that is stamped on each trace and saved with archived data. S810D/S820D utilizes vector error correction solving the most common and the most difficult accuracy problems of field test equipment operation, thus, improves system quality and reduces maintenance expenses. Vector error correction and a simple user interface within the S810D/S820D further improves the quality and convenience of measurements compared to traditional scalar techniques. An "anytime, anywhere" solution designed for the rugged challenges faced by field technicians working with wireless and defense communications systems.